Deprecate Xfinity Gateway integration (ADR-0004)

[frenck]

Breaking change

The Xfinity Gateway integration has been deprecated and pending removal in Home Assistant Core 0.109. It relies on web scraping to function, which is no longer allowed.

Proposed change

Deprecate Xfinity Gatway, since it relies on web scraping, the code owner suggested on deprecating and removing it (#31926).

ADR-0004.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example entry for configuration.yaml:

# Example configuration.yaml

Additional information

• This PR fixes or closes issue: fixes Xfinity Gateway integration violates ADR-0004 #31926
• This PR is related to issue:
• Link to documentation pull request: Deprecate Xfinity Gateway integration (ADR-0004) home-assistant.io#12138

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[probot-home-assistant]

Hey there @cisasteelersfan, mind taking a look at this pull request as its been labeled with a integration (xfinity) you are listed as a codeowner for? Thanks!